In 3GPP LTE networks, a base station (i.e. evolved NodeB, eNB) of a Radio Access Network (RAN) transmits data and signalling between a core network (CN) and User Equipment (UEs) located within the base station's coverage area. Base stations of a RAN typically include a number of ‘regular’ or ‘macro’ base stations and a number of ‘small cell’ or ‘pico’ base stations (often referred to as low power nodes, LPNs). In LTE, the RAN is referred to as the Evolved Universal Terrestrial Radio Access (E-UTRA) network (E-UTRAN) and the core network is referred to as the Evolved. Packet Core (EPC) network. User equipment may comprise, for example, mobile telephones, mobile communication devices, user communication devices, laptop computers, and/or the like.
In LTE networks, a number of different load metrics can be exchanged between neighbouring base stations by means of a suitable base station to base station interface, such as an ‘X2’ interface and/or the like. As described in sections 9.1 and 9.2 of 3GPP TS 36.423, such load metrics include one or more of:                Composite Available Capacity (CAC);        Physical Resource Block (PRB) usage: i) for Guaranteed Bit Rate (GBR) bearers; ii) for non-GBR bearers; or iii) both;        Transport Network Layer (TNL) load; and        hardware (HW) load.        
Each of these measurements can be reported separately for the (UL) and the Downlink (DL).
The so-called Mobility Load Balancing (MLB) function is responsible for optimising the mobility parameter configuration of the network nodes (e.g. base stations) in order to balance the distribution of load in the network. The MLB relies on information, including the above metrics, exchanged between neighbouring base stations.
Generally, the base station initiating the load balancing procedure determines which measurements need to be reported by which base station(s) and processes the reported measurements in order to determine whether it is necessary to adjust any associated mobility parameters. Typically, the MLB function performs offloading if the load in the served cell is at least a margin greater than the load reported by the neighbour cell. The purpose of the margin is to prevent oscillations and too frequent parameter changes. Although the different load metrics may be correlated, there might still be imbalances in opposite directions between two cells when different metrics or link directions (uplink/downlink) are considered by the MLB function.
Such imbalances may result in conflicts between the base stations, i.e. the base station operating cell A may try to offload towards cell B whilst, either simultaneously or subsequently, the base station operating cell B may try to offload towards cell A.